Greenfield said. “If we want to develop a variety of skills, we need a balanced media diet. Each medium has costs and benefits in terms of what skills each develops.”

Among the studies Greenfield analyzed was a classroom study showing that students who were given access to the Internet during class and were encouraged to use it during lectures did not process what the speaker said as well as students who did not have Internet access. When students were tested after class lectures, those who did not have Internet access performed better than those who did.

More than 85 percent of video games contain violence, one study found, and multiple studies of violent media games have shown that they can produce many negative effects, including aggressive behavior and desensitization to real-life violence, Greenfield said in summarizing the findings.

In another study, Video game skill predicted laparoscopic surgery skills, Greenfield said. “The best video game players made 47 percent fewer errors and performed 39 percent faster in laparoscopic tasks than the worst video game players.”

Visual intelligence has been rising globally for 50 years. Greenfield believes much of this change is related to our increased use of technology, as well as other factors, including increased levels of formal education, improved nutrition, smaller families and increased societal complexity etc.